knowledge of tundish lining refractories

Tundish definition:
The tundish is a refractory container, which first receives the molten steel poured from the ladle and is then distributed by the tundish outlet to each mold.
Tundish effect
(1) to reduce the static pressure of molten steel to maintain the stability of the tundish molten steel surface, the smooth injection of molten steel into the mold;
(2) to promote the inclusions in the molten steel to further float to clean the molten steel;
(3) diversion of molten steel. For multi-stream caster, the molten steel is distributed to each mold through the tundish.
(4) storage of molten steel. In the multi-furnace even after the replacement of ladle without reducing the speed, for the furnace to create conditions for continuous casting. ^
It can be seen that the role of tundish is mainly decompression, steady flow, to inclusions, storage and> "shunt molten steel.
Tundish lining refractory composition
Generally include the following:
(1) insulation layer (10 ~ 30mm), the layer next to the tundish steel shell, usually using asbestos board, insulation brick or light castable. The best effect for the aluminum silicate fiber mat, thermal conductivity is low, but also easy to masonry.
(2) permanent layer (100 ~ 200mm), the layer and the insulation layer in contact with the material is generally clay brick. The overall permanent lining is the most common, castable materials are generally high-alumina or mullite gravity castable.
(3) working layer (20 ~ 50mm), the layer in contact with molten steel, is the key parts. Widely used insulation boards or coatings. Insulation board is generally siliceous, magnesia, forsterite; coating for the magnesia, magnesia chrome, magnesium calcium. Coatings are mechanically sprayed or hand-painted.
(4) Block bricks, mosaic in the middle of the middle package, the installation of tundish outlet, the material is usually high aluminum.
(5) at the end of the package, the material is basically the same with the working layer, the middle of the package at the end of the working layer by the impact of molten steel parts easily damaged, requiring anti-erosion wear, generally with high alumina brick or dense high alumina brick and aluminum Chrome bricks, also with specially made large pieces of high strength tar grit. The impact of steel parts with zircon brick or prefabricated block enhanced.
(6) cover covered in the tundish, can be insulated and molten steel splash and other effects, the material used clay or high-alumina castable for cover.
(7) Slag wall (weir), the wall in the tundish, can be a single wall, it can be double walls. Slag wall weir material, usually high alumina bricks, can also be made of prefabricated blocks, the purpose is to block the. In order to improve the cleanliness of molten steel, in the slag wall can also be set on the molten steel filter.